Blister-packs are carded packaging where goods such as toys, hardware, dry pharmaceuticals, hard candy and electrical items are contained in between a specially made paperboard and clear pre-formed plastic cells such as poly vinyl chloride (PVC) and poly ethylene terepthalate (PET). The pre-formed plastic cell is affixed to the card using heat and pressure to activate a blister-coating coated on paperboard substrates. The adhesive bond formed between the paperboard and the plastic blister-is strong enough so that the blister-pack may hang on a peg. The blister-pack is teared open by hand to access the item packed inside. Solvent-based blister-coatings are used as they provide gloss to the printed material on the paper board and these coatings suffer the disadvantages of having high volatile organic contents (VOCs).
Water-based blister-coatings have been developed that have low VOCs. Disadvantages of these coatings are longer drying times and higher energy is required to evaporate water contents of 40-60% present in coating compositions. Also these solvent based coatings have poor gloss characteristics. Furthermore, resins and plasticizers are added to improve adhesion and reduce the block resistance of these coatings.
Given the above it would be advantageous to develop radiation cured blister-coatings that are heat sealable and overcome the limitations of water based blister-coatings and have low to no VOC's.